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import os
import inspect
import unittest
import imath

import IECore

import Gaffer
import GafferImage
import GafferImageTest

class SaturationTest( GafferImageTest.ImageTestCase ) :

	def test( self ) :
		i = GafferImage.Constant()
		i["color"].setValue( imath.Color4f( 1, 0, 0, 1 ) )

		ref = GafferImage.Constant()

		sat = GafferImage.Saturation()
		sat["in"].setInput(i["out"])

		# Test default passthrough
		self.assertEqual( sat["out"].channelDataHash( "R", imath.V2i( 0 ) ), i["out"].channelDataHash( "R", imath.V2i( 0 ) ) )
		self.assertImagesEqual( sat["out"], i["out"] )

		# Test fully desaturating each channel
		sat["saturation"].setValue( 0 )
		self.assertNotEqual( sat["out"].channelDataHash( "R", imath.V2i( 0 ) ), i["out"].channelDataHash( "R", imath.V2i( 0 ) ) )
		ref["color"].setValue( imath.Color4f( 0.2126, 0.2126, 0.2126, 1 ) )
		self.assertImagesEqual( sat["out"], ref["out"] )

		i["color"].setValue( imath.Color4f( 0, 1, 0, 1 ) )
		ref["color"].setValue( imath.Color4f( 0.7152, 0.7152, 0.7152, 1 ) )
		self.assertImagesEqual( sat["out"], ref["out"] )

		i["color"].setValue( imath.Color4f( 0, 0, 1, 1 ) )
		ref["color"].setValue( imath.Color4f( 0.0722, 0.0722, 0.0722, 1 ) )
		self.assertImagesEqual( sat["out"], ref["out"] )

		# Test increasing/decreasing saturation
		i["color"].setValue( imath.Color4f( 0.6, 0.5, 0.5, 1 ) )
		ref["color"].setValue( imath.Color4f( 0.52126, 0.52126, 0.52126, 1 ) )
		self.assertImagesEqual( sat["out"], ref["out"] )

		sat["saturation"].setValue( 2 )
		ref["color"].setValue( imath.Color4f( 0.67874, 0.47874, 0.47874, 1 ) )
		self.assertImagesEqual( sat["out"], ref["out"], maxDifference = 1e-7 )
